1. Field of the Invention
The present invention relates to zero clearance fireplaces of the type usually installed close to an outside wall of a room to be heated and haVing an exhaust stack which preferably exits through the close outside wall or through a ceiling and roof using an extension chimney. More particularly, the present invention relates to a prefabricated and factory built direct-vented zero clearance fireplace having one or more airtight glass side walls and a highly efficient, high BTU output gas burner and employs a novel combustion chamber that convection cools the glass side walls to avoid breaking the glass.
2. Description of the Prior Art
In our U.S. Pat. No. 4,793,322 a zero clearance fireplace is shown and described which has a highly efficient heat exchanger combined with a gas burner system that meets all of the American National Standard Institute's specifications for gas appliances in ANSI specification Z21.50 and Z21.60. These specifications have been adapted by the American Gas Association (AGA) design certification standards for direct vented multiglass side fireplaces.
Our U.S. Pat. No. 4,852,548 shows and describes a universal fireplace of the type adapted to be used with wood burning systems or a gas burning system. One of the objects of the invention of this latter patent is to provide novel cooling means and combustion gas diverting means for cooling low temperature tempered glass panels which are provided in the doors instead of expensive high temperature glass.
These two prior art patents are concerned with low to medium BTU output burners and fireplace heaters which fall into the range of 15 to 27,000 BTUs. This amount of heat is insufficient to heat a small home or a vacation home or an apartment and when installed in such homes or living units must be augmented by other heating systems.
It would be extremely desirable to provide a high BTU zero clearance fireplace with a gas burner system having sufficient heat output to heat a small home or apartment without auxiliary heating means and which is provided with decorative multiglass side walls and produces high efficiency with low carbon monoxide and provides a low glass side wall temperature meeting all requirements of the ANSI and AGA.